Hydraulic fan drive system

Abstract

Abstract A vehicle engine accessory drive system is disclosed including a hydraulic fan motor and a power steering gear mechanism in series flow relationship. The vehicle power steering pump is the sole source of fluid for the system and has its flow control setting at a flow rate X, which is substantially greater than the flow rate Z required by the power steering gear. A temperature responsive bypass valve is connected in parallel across the fan motor and the bypass flow and motor outlet flow recombine, then flow to a steering gear flow control which communicates a flow rate Z to the steering gear mechanism and all fluid in excess of Z bypasses the steering gear, recombining with the output flow from the steering gear and returning to the pump inlet. This system provides a flow to the fan motor resulting in a fan speed-versus-engine speed similar to a "viscous curve". In addition, the system permits simultaneous operation of the fan motor and steering gear without the flow requirement of either one affecting the flow to the other, and with the pressure requirements being complementary, i.e., the pressure drop across the fan motor is at a minimum when the steering load is at a maximum.

Inventors

• 👤 E Goscenski

Bibliographic Details